Post-earthquake dizziness syndrome following the 2016 Kumamoto earthquakes, Japan

This study aimed to examine the types and causes of dizziness experienced by individuals after a major earthquake. This cross-sectional study enrolled healthy participants who experienced the 2016 Kumamoto earthquakes and their aftershocks. Participants completed a questionnaire survey on their symptoms and experiences after the earthquakes. The primary outcome was the occurrence of dizziness and the secondary outcome was the presence of autonomic dysfunction and anxiety. Among 4,231 eligible participants, 1,543 experienced post-earthquake dizziness. Multivariate logistic regression analysis revealed that age (≥21, P < .001), female sex (P < .001), floor on which the individual was at the time (≥3, P = .007), tinnitus/ear fullness (P < .001), anxiety (P < .001), symptoms related to autonomic dysfunction (P = .04), and prior history of motion sickness (P = .002) were significantly associated with the onset of post-earthquake dizziness. Thus suggesting that earthquake-related effects significantly affect inner ear symptoms, autonomic function, and psychological factors. Earthquake-induced disequilibrium may be further influenced by physical stressors, including sensory disruptions induced by earthquake vibrations, changes in living conditions, and autonomic stress. This study increases our understanding of human equilibrium in response to natural disasters.